Method and apparatus for accelerated catalyst poisoning and deactivation

ABSTRACT

An article, apparatus and method for simulating poisoning and deactivating catalysts with catalyst poison compounds at least one catalyst poison compound selected from the group consisting of a compound comprising phosphorous, a compound comprising zinc compound and a compound comprising phosphorous and zinc. 4793

BACKGROUND OF THE INVENTION

[0001] 1. Field Of The Invention

[0002] The present invention relates to a method and apparatus usefulfor evaluation of catalysts. More particularly, the present invention isdirected to simulating poisoning and deactivating catalysts withcatalyst poison compounds at least one catalyst poison compound selectedfrom the group consisting of a compound comprising phosphorous, acompound comprising zinc compound and a compound comprising phosphorousand zinc.

[0003] 2. Description of the Related Art

[0004] The art discloses that additives such as lubricants used ininternal combustion engine oils can contain compounds which containphosphorous and/or zinc. Such compounds include materials such as zincdialkyldithiophosphate also referred to as zinc dithiophosphate (ZDTP)and zinc dithiocarbamate (ZDTC). Other disclosed zinc and phosphorousadditives to oil include metallic detergents including phosphorares andphosphorous compounds included as extreme pressure agents. Reference ismade to U.S. Pat. Nos. 4,674,447 and 5,696,065 and European ApplicationNo. 95309415. The phosphorous and zinc are disclosed to lower thefunction of the motor vehicle exhaust treatment catalyst.

[0005] As engine technology and exhaust gas treatment technology hasimproved engines pass less lubricating oil, including phosphorous andzinc compound to the catalysts and the catalysts have been sufficientlyactive to treat exhaust gases in accordance with various governmentregulations. However, as engine performance continues to increase andenvironmental regulations become more stringent catalysts activity willhave to be increased and maintained with longer engine life. As enginelife increases there will be a greater build up of compounds,particularly phosphorous and/or zinc compounds passing to the emissiontreatment catalyst from the engine. It is desirable to have a method tosimulate the poisoning of the catalyst poisoning and deactivation in thelaboratory for different engine systems run at different conditions tofor various reasons including to more rapidly screen new catalysts.

[0006] Numerous methods have been used in the past to simulate long termdeactivation of a catalyst, using an engine bench test. Most of thesemethods involve running an engine at very high speed and load conditionscyclically for several hours, often creating a large exotherm in thecatalyst bed during certain portions of the test cycle. These adverseconditions deactivate the catalytic converter, and a correlation isdrawn between this type of rapid aging cycle and on-road deactivation ofthe emission control system in general, and catalytic converter, inparticular. While such correlations can be developed, they do not alwaysmimic the actual deactivation modes, such as poison accumulation.

[0007] References such as U.S. Pat. No. 4,771,029 disclose the adrecognition of catalyst poisoning by materials such as phosphorous. U.S.Pat. No. 4,727,746 discloses a modal mass analysis method for simulatingdriving conditions for evaluating exhaust gases.

[0008] Ueda et al., Engine Oil Additive Effects on Deactivation ofMonolithic Three-Way Catalysts and Oxygen Sensors, SAE, SP-1043, 1994,discloses that it is widely known that ZDTP results in phosphorouspoisoning of three-way emissions catalysts. Catalysts and oxygen sensorswere “poisoned” on the engine bench by test oils, varying the quantityof phosphorous and ash. The performance of the catalysts and sensors wasevaluated using a FTP test on a chassis dynamometer. It was found thatcalcium and magnesium helped prevent the phosphorous from adhering tothe catalyst.

[0009] Joy et al., The Influence of Sulfur Species on the LaboratoryPerformance of Automotive Three Component Control Catalysts, SAE, 1979,discloses that poisons such as phosphorous and sulfur poison catalysts.Studies were done in the laboratory on the effects of sulfur dioxide.

[0010] Baba et al., Numerical Simulation of Deactivation Process ofThree-way Catalytic Converters, SAE, SP-1533, Mar. 6, 2000, discloses anumerical simulation method to predict the deactivation process ofthree-way catalytic converters. Based on simulated results of thedeactivated state inside the bench aged catalysts, which are noble metalparticle size and catalyst activity distributions, thermal responses andlight-off behaviors during warm-up tests are predicted.

[0011] Natoli et al., Three-way Catalyst Deactivation by LubricantsDuring Fast Aging Engine Tests, Gionale ed Atti della AssociazioneTechnica dell'Automobile, Vol. 48, No. 12, p 685, 1995 discloses thatengine lubricants play an important role in poisoning three-waycatalytic converters. The objective was to reproduce in the laboratorythe aging of the catalysts under accelerated conditions in order toevaluate the influence of additive contained in engine oils.

[0012] Ball et al., Application of accelerated Rapid Aging Test (RAT)Schedules with Poison: The Effects of Oil Derived Poisons, ThermalDegradation and catalyst Volume on FTP Emissions, SAE, SP-1296, 43-53,1997 discloses dynamometer rapid aging tests incorporate both thermaland oil-derived poison degradation are used to age catalysts for FTPemissions studies. Vehicle aged converters are analyzed to determine theaxial aged phosphorous distribution throughout the catalyst. Theseprofiles are compared to dynamometer aged RAT aged catalysts.

[0013] Other references of interest include: Carol et al., Hightemperature Deactivation of Three-way Catalyst, SAE, 1989; Pattas etal., Computer Aided Assessment of Catalyst Aging Cycles, SAE, 1995. Becket al., Impact of Oil-derived Catalyst Poisons on FTP Performance of LEVCatalyst Systems, SAE, SP-1296, 1-10, 1997. Jobson et al., Deteriorationof Three-way Automotive Catalysts, SAE, SP-957, 153-66, 1993; andWilliamson et al., Effects of Oil Phosphorous on Deactivation ofMonolithic Three-way Catalysts, Appl. Catal. (1985), 15(2), 277-92.

SUMMARY OF THE INVENTION

[0014] Automotive catalytic converters and filters comprise at least onecatalyst composition. Such catalyst compositions are susceptible topoisoning due to lubricant oil—derived phosphorus, zinc, sulfur andother compounds. Catalyst compositions (referred to as “catalysts”) canbe coated on to a suitable substrate. The coated catalyst when appliedto the substrate in a slurry or liquid form is also referred to as a“washcoat”. The poisons may accumulate on the surface of the washcoat,creating a physical barrier, or they may interact with the catalyticmaterial in the washcoat, resulting in loss of catalytic activity,and/or become a barrier to particulate filters such as foam, screens andwallflow filters. The poison level and type can vary, depending upon thedesign of the engine and the operating conditions. In the development ofthe emission control system, it is critical to know the type of poison aexposure and the impact of poison on the emissions control system ingeneral, and the catalytic converter, in particular.

[0015] The present invention relates to a method and apparatus thateffectively duplicates these poisoning conditions in a laboratoryenvironment. In addition, the invention relates to a method andapparatus that duplicates, on an engine test stand, the equivalent ofextended on road-type poison exposure, deposition and catalystdeactivation and/or filter clogging.

[0016] It is generally known that lubricant-derived phosphorus, zinc andsulfur can accumulate on the catalyst surface and result indeactivation. This poisoning mechanism is quite complex, and highlydependent upon the operating temperature, the oil consumption of theengine, and the source of the oil consumption. For example, when oilleaks past the piston rings, and washes into the combustion chamber, itgoes through the combustion process. This will result in certain typesof phosphorus and/or zinc compounds (among other contaminants).Particular compounds may have a certain type of deactivation effect onthe catalytic converter, depending upon the operating condition. On theother hand, oil that leaks past the exhaust valve guide and stem, maynot go through the combustion process, and result in a different type ofpoisoning of the catalytic converter.

[0017] Numerous methods have been used in the past to simulate long termdeactivation of a catalyst, using an engine bench test. Most of thesemethods involve running an engine at very high speed and load conditionscyclically for several hours, often creating a large exotherm in thecatalyst bed during certain portions of the test cycle. These adverseconditions deactivate the catalytic converter, and a correlation isdrawn between this type of rapid aging cycle and on-road deactivation ofthe emission control system in general, and catalytic converter, inparticular. While such correlations can be developed, they do not alwaysmimic the actual deactivation modes, such as poison accumulation. Inthis invention, a method has been developed to accelerate the catalystaging process, with poison deposition on an emission treatment devicewhich are typically a catalyst and/or a filter. The catalyst can be acatalyst composition in self supported form such as a powder, pellet orother form article, or in a supported form wherein the catalystcomposition is supported on a suitable substrate such as a monolithicarticle which can be a metallic or ceramic flow through or wall flowhoneycomb, wire mesh and ceramic foam.

[0018] In accordance with the method of the present invention, anemission treatment device selected from at least one of a catalyst and afilter, is combined with at least one poison compound having at leastone component selected from the group consisting phosphorous, zinc andsulfur to form a poisoned emission treatment device.

[0019] The poisoned emission treatment device is heated at suitabletemperatures, typically from about 200° C. to about 1100° C., preferablyfrom about 300° C. to about 800° C., more preferably from about 300° C.to about 500° C., most preferable about 400° C. for a sufficient time tocalcine poisoned device. Typically the calcination time is from about0.5 hours to about 24 hours preferably from about 1.0 hours to about 12hours, more preferably from about 2.0 hours to about 8.0 hours, mostpreferable from about 3.0 hours to about 6.0 hours to form a calcinedemission treatment device. The activity of the calcined emissiontreatment device can then be evaluated. The evaluation can includeevaluating catalytic activity of an exhaust treatment catalyst todetermine the conversion percent of at least one pollutant component bythe catalyst, the light-off temperature of at least one pollutantcomponent at a catalyst, and/or the efficiency of a filter.

[0020] In a specific embodiment, accordance with the method of thepresent invention the emission treatment device can be combined withpoisons provided by a the operation of a gasoline or diesel engine,having an exhaust gas outlet or an exhaust gas manifold outlet. Theengine can be on a bench stand in the laboratory or on a motor vehicle.An exhaust gas stream comprising pollutants selected at least onepollutant component selected from the group consisting of carbonmonoxide, hydrocarbons and nitrogen oxides, volatile organic componentsand dry soot, from the exhaust gas outlet or the exhaust gas manifoldoutlet of the engine is passed to the emission treatment device. Atleast one poison compound having at least one component selected fromthe group consisting phosphorous, zinc and sulfur can be added to theexhaust gas stream at a location between the exhaust gas outlet or theexhaust gas manifold outlet and the emission treatment device. Theexhaust gas containing the poison compound can then contact the emissiontreatment device to form a poisoned emission treatment device. Theemission treatment device can then be evaluated.

[0021] In another specific embodiment the gasoline or diesel engine havean oil pan in which lubricating oil is located. At least one poisoncompound having at least one component selected from the groupconsisting phosphorous, zinc and sulfur is added to the oil in an amountin excess of the amount functionally required for the oil to function.The emission treatment device can then be evaluated.

[0022] In an alternative and preferred embodiment, the emissiontreatment device can be combined with at least one poison compound orprecursor compound having at least one component selected from the groupconsisting phosphorous, zinc and sulfur. The poison or poison precursorcan be applied directly to the emission treatment device. The device canthen be calcined. Where the device is a filter or catalyzed substratethe poison or poison precursor can be coated with a solution or slurry,sprayed, or deposited by other suitable methods. The poisoned device canthen be evaluated. In preferred embodiments, catalyzed substrates arecoated with a slurry containing the poison or poison precursor. Thecoated substrate can be calcined, if necessary, and then evaluated. Thisprovided a rapid way to screen the effect of poisons on various catalystcompositions. The method is particularly useful to evaluate thecatalysts useful as gaseous emissions exhaust catalyst. Such catalyststypically are used to treat at least one pollutant component selectedfrom the group consisting of carbon monoxide, hydrocarbons and nitrogenoxides, volatile organic components and dry soot.

[0023] In an alternative embodiment the emission treatment device (e.g.,the catalyst) to be aged is mounted on an engine test bench. Thelubricating oil in the engine may be doped with high levels of catalystpoison or poison precursor such as zinc dialkyl dithiophosphate (ZDDP),a commercially available phosphorus/Zinc/Sulfur compound. Alternativelyor in combination, an apparatus can be set up to inject ZDDP-containingengine oil directly into the exhaust stream, ahead of the catalyticconverter. The level of ZDDP and the amount of oil injected can bevaried, depending upon the degree of deactivation required. The enginecan then run through a combination of high speed and load (to thermallydeactivate the catalyst), and low speed/low load conditions combinedwith injection of the oil into the exhaust stream (to deposit thepoisons on the catalytic surface). This combination of high and lowtemperature operation is run cyclically or sequentially, until thedesired level of deactivation is achieved. In general, exhaust gastemperatures during accelerated aging on an engine dynamometer or alaboratory reactor can be vary, from about 300° C. during low load andlow speed operation, and up to about 1200° C. during high load and highspeed operation. More specifically, the exhaust gas temperatures can bevary, in the range of 300° C. to 1200° C. Alternatively, operatingranges can be from about 300° C. to about 600° C. during low speed andlow load operation, or from about 600° C. to about 1200° C. during highspeed and high load operation.

[0024] The present invention includes a method of introducing thepoison-containing oil into the exhaust stream at the above conditions.The process of introducing engine lubricating oil (with or withoutelevated levels of poisonous compounds) is critical. For instance, ifoil is dripped or injected into the exhaust stream, it could coke oroxidize at the point of introduction, and may 1) never reach thecatalyst washcoat surface, or 2) coke and block the nozzle or otherdevice used to drip or inject the oil into the exhaust stream.

[0025] In accordance with the method of the present invention, coking ofoil in the process of accelerated aging of a catalytic converter on anengine dynamometer or a laboratory reactor is prevented or minimized.Forcing the oil in to the exhaust stream as a mist with the assistanceof high pressure nitrogen or other inert gas is one embodiment of thepresent invention. This assists in keeping the flow nozzle clear duringcertain types of catalyst aging.

[0026] Another embodiment of this invention is the introduction of bothhigh pressure nitrogen (or other inert gas) and water with the oil. Theoil, water and nitrogen have to be introduced at predetermined rates andpressures, sufficient to keep a clear flow through the injection nozzleor orifice. This method results in the emulsification of the oil by thewater. As the mixture comes in contact with the hot walls of theinjector and tube, some coking will begin. However, the water in theemulsion evaporates at these temperatures, and thus cleans out the oilflow passage. This self-cleaning mechanism is preferred to keeping acontinuous flow of oil into the exhaust gas stream for the entireduration of oil injection during certain arduous the accelerated agingtest protocol.

[0027] The method and apparatus of the present invention areparticularly useful when the emission treatment device comprises acatalyst supported on a substrate. In preferred embodiments the catalystcomprises a catalyst composition comprising a support; and at least onecatalytic material selected from the group consisting of at least oneplatinum group metal component, gold and silver. The platinum groupmetal component can be selected from at least on component selected fromthe group consisting of platinum, palladium, rhodium, ruthenium andiridium.

[0028] The method is useful to evaluate the effect of poisons selectedfrom the group of a compound comprising phosphorous, a compoundcomprising zinc compound, a sulfur compound, a compound comprisingphosphorous and zinc, a compound comprising zinc and sulfur and acompound comprising phosphorous zinc and sulfur. Typically, thecompounds comprising phosphorous are selected from the group consistingof ammonium hydrophosphate, phosphoric acid, phosphorus acid, and organophosphorus compounds; compounds comprising zinc is selected from thegroup consisting of zinc oxide, zinc nitrate, zinc sulfate, zinccarbonate and organo zinc compounds; and the compound mixturescomprising phosphorous, and zinc can be selected from the groupconsisting of a mixture of zinc oxide and ammonium hydrophosphate, zincdithio phosphate, and zinc phosphate.

[0029] Where the poison is added to the lubricating oil, it will be inexcess of the amount typically in lubricating oil. The amount of poisonor poison precursor is typically greater than about 0.15 weight percentof the oil and poison or poison precursor, and preferably from about0.15 to 0.5, more preferably from 0.2 to 0.5 poison or poison precursor.

[0030] In a preferred method the compound mixture comprising phosphorousand zinc and optionally sulfur compounds is a in a slurry. A preferredmixture is an aqueous slurry of zinc oxide and ammonium hydrophosphate.The slurry is then coat applied, typically by coating or spraying on toa catalyst which is preferably a catalyst composition located on asubstrate, on to a filter such as a wall flow filter. As necessary, andpreferably the poisoned is calcined.

[0031] In typical evaluations the amount of the catalyst poison compoundis from about 1.0 to about 20 weight percent of the catalyst.

[0032] The step of evaluating the catalytic activity of the gaseousemissions exhaust catalyst comprises contacting a synthetic gascomprising at least one pollutant component with the poisoned catalystat predetermined conditions of temperature, time and pollutant componentconcentration to determine the conversion percent of at least onepollutant component and/or the light-off temperature of at least onepollutant component. The catalyst can have poison added at apredetermined rate. Catalyst light off is the temperature at which 50%conversion of a given pollutant is converted. This can be determinedusing flame ionization detector to measure hydrocarbon conversion.Carbon monoxide conversion can be measured using nondispersive infrared(NDIR) analysis. Nitrogen oxide conversion can be determined using achemiluminescence analyzer.

[0033] Pressure drop, weight game, micro photographs can be used toassess the effect of poison as becoming a barrier to a filter.

[0034] The present invention further includes as an article, an emissiontreatment device selected from at least one of a catalyst and a filter.The emission treatment device has an over coat of a predetermined amountat least one poison or poison precursor compound having at least onecomponent selected from the group consisting phosphorous, zinc andsulfur.

[0035] Where the article comprises an exhaust treatment catalyst. Thecatalyst comprises a composition having a support and at least oneplatinum group metal component selected from the group consisting ofplatinum, rhodium, ruthenium and iridium components.

[0036] In a specific embodiment the article comprises a catalystsupported on a substrate having channel extending from an inlet end toan outlet end and the poison is deposited in varying concentrations fromthe inlet to the outlet. The poison can be deposited in zones havingdifferent concentrations from the inlet to the outlet. The poison can bedeposited in an inlet zone having a higher concentrations then an outletzone located between the inlet zone and the outlet end.

[0037] The present application further includes an apparatus comprisinga gasoline or diesel engine, having an exhaust gas outlet or an exhaustgas manifold outlet. There is an emission treatment device selected fromat least one of a catalyst and a filter. A conduit communicates betweenthe exhaust gas outlet or an exhaust gas manifold outlet and theemission treatment device. An overcoat on the catalyst composition has apredetermined amount of at least one poison compound or poison precursorhaving at least one component selected from the group consistingphosphorous, zinc and sulfur. There is feed port into the conduit at alocation between the exhaust gas outlet or the exhaust gas manifoldoutlet and the emission treatment device; and a means to feed throughthe feed port at least one poison or a compound capable of forming thepoison and having at least one component selected from the groupconsisting phosphorous, zinc and sulfur. There is a means to evaluatethe emission treatment device to determine the conversion percent of atleast one pollutant component by the catalyst, the light-off temperatureof at least one pollutant component at the catalyst, and/or theefficiency of the filter.

BRIEF DESCRIPTION OF DRAWINGS

[0038]FIG. 1 is a general schematic diagram of catalyst aging system ofthe present invention.

[0039]FIG. 1A is a schematic diagram of a injection system, useful toinject nitrogen, oil and water into an engine exhaust stream, upstreamof the exhaust treatment catalyst.

[0040]FIG. 2 is a microprobe X-ray map of zinc and phosphorus fresh asdeposited on surface of washcoat in Example 2.

[0041]FIG. 3 is a microprobe X-ray map of zinc and phosphorus profilesafter 1050 C aging in air in Example 2.

[0042]FIG. 4 is a microprobe X-ray map of samples showing laboratorytested versus engine tested phosphorus profiles in Example 2.

[0043]FIG. 5 is a graph showing a reference sample versus Zn/P dopedcatalyst sample in a lab reactor light off test comparison in Example 4.

[0044]FIG. 6 is a graph showing a reference sample and Zn/P dopedcatalyst sample in a lab reactor light off text after 1050 C. aging inExample 4.

[0045]FIG. 7 is a graph showing HC light off tests on catalysts aged onexothermic cycle alone in Example 4.

[0046]FIG. 8 is a graph showing HC light off curves with and without oilinjection into exhaust stream in Example 5.

[0047]FIG. 9 is a graph showing HC light off test for catalysts agedwith and without oil injection into exhaust stream in Example 5.

[0048]FIG. 10 is a graph showing FTP tailpipe HC emissions for catalystsaged with and without oil injection in Example 5.

[0049]FIG. 11 is a graph showing FTP tailpipe CO emissions for catalystsaged with and without oil injection in Example 5.

[0050]FIG. 12 is a graph showing FTP tailpipe NOx emissions forcatalysts aged with and without oil injection in Example 5.

[0051]FIG. 13 is a schematic cross-sectional view of a catalyzedsubstrate channel with a poison coating on the catalyst in zones ofpoison from the inlet to the outlet.

[0052]FIG. 14 is graph illustrating engine aging with and without oilinjection in Example 6.

[0053]FIG. 15 is a microprobe X-ray maps of a sample showing enginetested phosphorus profiles with oil injection in Example 6.

[0054]FIG. 16 is a microprobe X-ray maps of samples showing enginetested phosphorus profiles without oil injection in Example 6.

[0055]FIG. 17 is a graph showing HC light off curves with and withoutoil injection into exhaust stream in Example 7.

[0056]FIG. 18 is a microprobe X-ray maps of a sample showing enginetested phosphorus profiles with oil injection in Example 7.

[0057]FIG. 19 is a microprobe X-ray maps of samples showing enginetested phosphorus profiles without oil injection in Example 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0058] The present invention will be understood by those skilled in theart by reference to following description of the preferred embodimentsincluding the examples, and the accompanying drawings.

[0059] This invention, relates to an apparatus and method to acceleratethe catalyst aging process, with poison deposition on an emissiontreatment device which are typically a catalyst and/or a filter.

[0060]FIG. 1 is a schematic drawing of an apparatus of the presentinvention. In this embodiment there is an engine 10 in communicationwith an oil pan 12. The engine 10 can powered by a fossil fuel and be agasoline, gasohol, or diesel engine. The engine has a engine exhaust gasoutlet 14. Alternatively, but not shown the engine can have an exhaustgas manifold having a exhaust manifold outlet. There is an emissiontreatment device 16 selected from at least one of a catalyst, a filter,and a catalyzed filter. A suitable conduit, such as exhaust pipe 15,communicates between the exhaust gas outlet 14 and the emissiontreatment device 16. There is an over coat of a predetermined amount atleast one poison compound, or precursor therefor, having at least onecomponent selected from the group consisting phosphorous, zinc andsulfur.

[0061] In one embodiment of the present invention one poison compound,or precursor therefor can be fed to emission treatment device 16 fromoil pan 12 through the engine 10. Alternatively, or in combination thepoison compound, or precursor therefor can be fed into emissiontreatment device 16, preferably through a feed port 18 into the conduit20 at a location between the exhaust gas outlet 14 or the exhaust gasmanifold outlet and the emission treatment device 16. There is a meansto feed, such as a pump, to feed the feed port at least one poison or acompound capable of forming the poison. Finally, there is a means, notshown, to evaluate the emission treatment device to determine theconversion percent of at least one pollutant component by the catalyst,the light-off temperature of at least one pollutant component at thecatalyst, and/or the efficiency of the filter.

[0062]FIG. 1A is a schematic diagram of an injection system, useful toinject an inert gas such as nitrogen, oil and water into an engineexhaust stream 17, upstream of the exhaust treatment catalyst. Moreparticularly, nitrogen from a nitrogen reservoir 40, under a higherpressure than that in the exhaust pipe 15, is in communication, via anitrogen conduit 42, with a mixing manifold 44 which feeds into exhaustpipe 15 upstream of the emission treatment device 16. There can be acontrol means, such nitrogen valve 46 to control the flow of thenitrogen to the manifold 44.

[0063] Oil from an oil reservoir 50, can be pumped by oil pump 52 undera higher pressure than that in the exhaust pipe 15, is in communication,via a oil conduit 54, with mixing manifold 44. The oil pump can controlthe flow of the oil to the manifold 44.

[0064] Water from an water reservoir 60, can be pumped by water pump 62under a higher pressure than that in the exhaust pipe 15, is incommunication, via a water conduit 64, with mixing manifold 44. Thewater pump can control the flow of the water to the manifold 44. Auseful pump to pump the oil and water is an FMI brand; type QG20; with aCKC RH1 head. The mixing manifold 44 can be a suitable length anddiameter of metal pipe forming a sealed enclosed surface having anoutlet port in communication with the exhaust pipe 15. Preferably themanifold 44 is made of stainless steel. The length and diameter of thepipe can be varied as needed. The manifold 44 should have inlet portswhereby it is connected and in communication with gas conduit 42, oilconduit 54 and water conduit 64. A useful stainless steel manifold hasan outside diameter ranging from about ⅛ to about 1 inch, and preferablyabout ¼ inch. The wall thickness should be great enough to withstand thepressures and temperature of the testing environment, with a preferredwall thickness ranging from {fraction (1/16)} to ¼ inch, and preferablyabout {fraction (3/32)} inches.

[0065] Typical poisons which are addressed include compound containingpoison components such as mixtures (e.g., physically mixed compounds),chemical compound compositions (e.g., molecules containing), andcombinations thereof. The specific poisons of most concern compriseindividually or in combination one or more of phosphorous, zinc and/orsulfur components. The compounds to which the present invention isdirected can be the poison compound which ultimately poison an emissiontreatment device or precursor's therefor.

[0066] Typically, the source of the poison compounds is in lubricatingoils, although they can have other sources such as the sulfur compoundspresent in diesel fuel or in gasoline. The at least one poison compoundcan be selected from the group of a compounds comprising phosphorous, acompound comprising zinc compound, a sulfur compound, a compoundcomprising phosphorous and zinc, a compound comprising zinc and sulfurand a compound comprising phosphorous zinc and sulfur.

[0067] Specific poison compounds comprising phosphorous are selectedfrom the group consisting of ammonium hydrophosphate, phosphoric acid,phosphorus acid, and organo phosphorus compounds. Organic phosphorouscompounds include phosphines, phosphoranes, phosphonium salts. Otherphosphorous compounds include phosphorous sulfides and phosphoroushalides.

[0068] The compound comprising zinc can be selected from the groupconsisting of zinc oxide, zinc nitrate, zinc sulfate, zinc carbonate andorgano zinc compounds. Organic zinc compounds include zinc ester salts,zinc sulfonates.

[0069] The compound comprising phosphorous and zinc can be selected fromthe group consisting of a mixture of zinc oxide and ammoniumhydrophosphate, zinc dithio phosphate, and zinc phosphate.

[0070] Sulfur compounds can include a wide variety of sulfides, sulfatesand sulfonate, as well as sulfonic acids and their derivatives.

[0071] The method of the present invention is directed to simulating thepoisoning and deactivation of an emission control device selected fromat least one of a catalyst and a filter. The method has two approaches.The first approach is to combine a poison compound and an emissioncontrol device to form a simulated poisoned device. The second approachis to engine age the device with an engine having oil in the oil panwith increased amounts of the poison or poison precursor compounds.Alternatively, in accordance with the second approach the poison orpoison precursor compounds can be feed, preferably in combination withoil, directly into the device or into an exhaust conduit leading to thedevice.

[0072] The first approach can be conducted by directly adding the poisoncompound or poison precursor directly on to a device. This can beaccomplished by combining the emission treatment device with apredetermined amount of at least one poison compound or precursorcompound having at least one component selected from the groupconsisting phosphorous, zinc and sulfur. The poison or poison precursorcan be applied directly to the emission treatment device.

[0073] The device can then be calcined. The poisoned emission treatmentdevice is heated at suitable temperatures, typically from about 200° C.to about 1100° C., preferably from about 300° C. to about 800° C., morepreferably from about 300° C. to about 500° C., most preferable about400° C. for a sufficient time to calcine poisoned device. Typically thecalcination time is from about 0.5 hours to about 24 hours preferablyfrom about 1.0 hours to about 12 hours, more preferably from about 2.0hours to about 8.0 hours, most preferable from about 3.0 hours to about6.0 hours to form a calcined emission treatment device. The activity ofthe calcined emission treatment device can then be evaluated.

[0074] Where the device is a filter or catalyzed substrate the poison orpoison precursor can be coated with a solution or slurry, sprayed, ordeposited by other suitable methods. The poisoned device can then beevaluated. In preferred embodiments, catalyzed substrates are coatedwith a slurry containing the poison or poison precursor. The coatedsubstrate can be calcined, if necessary, and then evaluated. Thisprovided a rapid way to screen the effect of poisons on various catalystcompositions. The method is particularly useful to evaluate thecatalysts useful as gaseous emissions exhaust catalyst. Such catalyststypically are used to treat at least one pollutant component selectedfrom the group consisting of carbon monoxide, hydrocarbons and nitrogenoxides, volatile organic components and dry soot.

[0075] The first approach results in an article, an emission treatmentdevice, selected from at least one of a catalyst and a filter. Theemission treatment device has an over coat of a predetermined amount atleast one poison or poison precursor compound having at least onecomponent selected from the group consisting phosphorous, zinc andsulfur.

[0076] Where the article comprises an exhaust treatment catalyst. Thecatalyst comprises a composition having a support and at least oneplatinum group metal component selected from the group consisting ofplatinum, rhodium, ruthenium and iridium components.

[0077] In a specific embodiment referred to in FIG. 13, the articlecomprises a catalyst supported on a substrate 22 such a flow throughcatalyzed substrate, or wall flow filter which is optionally catalyzed,each having channel 24 defined by channel walls 26 (in the case of awall flow filter the channel is blocked on one end) extending from aninlet end 28 to an outlet end 30 and the poison compound or precursor isdeposited in varying concentrations from the inlet to the outlet. Thepoison can be deposited in zones 32, 34 and 36 having differentconcentrations and/or loading amounts from the inlet to the outlet. Thepoison is preferably deposited in an inlet zone 32 having a higherconcentrations or loadings then at the downstream zone 34 or the outletzone 36 located between the inlet zone and the outlet end.

[0078] The poison compound or poison precursor can be deposited indiscreet zone based on loadings or concentrations or in gradients fromthe inlet end 28 to the outlet end 30. Methods to zone coat the poisoncompound or poison precursor compound are analogous to zone coatingcatalysts and related materials on to monolithic honeycombs. Referenceis made to such methods disclosed in commonly assigned U.S. Ser. No.09/067,820, entitled Layered Catalyst Composite and published as WO99/55459 all herein incorporated by reference.

[0079] Other useful methods of zone coating for the present inventionare known. Such methods for zone coating monolithic honeycombscontaining different catalyst compositions in zones along the length ofthe honeycomb are also known for use in catalytic combustion processesfrom references such as WO 92/09848 herein incorporated by reference. Itis disclosed that graded catalyst structures can be made on ceramic andmetal monoliths by a variety of processes. Monoliths can be partiallydipped in washcoat and excess washcoat blown out of the channel. Theprocess is repeated by dipping further into the washcoat sol.Alternatively, catalyst is disclosed to be applied to metal foil whichis then rolled into a spiral structure. The washcoat is disclosed to besprayed or painted onto the metal foil or applied by other knowntechniques such as by chemical vapor deposition, sputtering, etc.

[0080] The second approach is to engine age the device with an enginehaving oil in the oil pan with increased amounts of the poison or poisonprecursor compounds. In accordance with this approach the emissiontreatment device can be combined with poisons provided by a theoperation of a gasoline or diesel engine, having an exhaust gas outletor an exhaust gas manifold outlet. The engine can be on a bench stand inthe laboratory or on a motor vehicle. An exhaust gas stream comprisingpollutants selected at least one pollutant component selected from thegroup consisting of carbon monoxide, hydrocarbons and nitrogen oxides,volatile organic components and dry soot, from the exhaust gas outlet orthe exhaust gas manifold outlet of the engine is passed to the emissiontreatment device. At least one poison compound having at least onecomponent selected from the group consisting phosphorous, zinc andsulfur can be added to the exhaust gas stream at a location between theexhaust gas outlet or the exhaust gas manifold outlet and the emissiontreatment device. The exhaust gas containing the poison compound canthen contact the emission treatment device to form a poisoned emissiontreatment device. The emission treatment device can then be evaluated.

[0081] In another embodiment of the second approach, the gasoline ordiesel engine have an oil pan in which lubricating oil is located. Atleast one poison compound having at least one component selected fromthe group consisting phosphorous, zinc and sulfur is added to the oil inan amount in excess of the amount functionally required for the oil tofunction. The emission treatment device can then be evaluated.

[0082] In the second approach, the level of poison such as ZDDP and theamount of oil injected can be varied, depending upon the degree ofdeactivation required. The engine is then run through a combination ofhigh speed and load (to thermally deactivate the catalyst), and lowspeed/low load conditions combined with injection of the oil into theexhaust stream (to deposit the poisons on the catalytic surface). Thiscombination of high and low temperature operation is run cyclically,until the desired level of deactivation is achieved.

[0083] In an alternative and preferred embodiment, the emissiontreatment device can be combined with at least one poison compound orprecursor compound having at least one component selected from the groupconsisting phosphorous, zinc and sulfur. The poison or poison precursorcan be applied directly to the emission treatment device. The device canthen be calcined. Where the device is a filter or catalyzed substratethe poison or poison precursor can be coated with a solution or slurry,sprayed, or deposited by other suitable methods. The poisoned device canthen be evaluated.

[0084] The step of evaluating the catalytic activity of the gaseousemissions exhaust catalyst comprises contacting a synthetic gascomprising at least one pollutant component with the poisoned catalystat predetermined conditions of temperature, time and pollutant componentconcentration to determine the conversion percent of at least onepollutant component and/or the light-off temperature of at least onepollutant component. The catalyst can have poison added at apredetermined rate. Catalyst light off is the temperature at which 50%conversion of a given pollutant is converted. This can be determinedusing flame ionization detector to measure hydrocarbon conversion.Carbon monoxide conversion can be measured using nondispersive infrared(NDIR) analysis. Nitrogen oxide conversion can be determined using achemiluminescence analyzer. Pressure drop, weight game, microphotographs can be used to assess the effect of poison as becoming abarrier to a filter. It is recognized that such methods of analysis arewell know in the emissions treatment art.

[0085] In accordance with the method of the present invention when usingthe system of FIG. 1A, the emission treatment device 16 (e.g., thecatalyst) to be aged is mounted on an engine test bench. The lubricatingoil in the engine 10 may be doped with high levels of catalyst poison orpoison precursor such as zinc dialkyl dithiophosphate (ZDDP), acommercially available phosphorus/Zinc/Sulfur compound. Alternatively orin combination, an apparatus can be set up to inject ZDDP-containingengine oil directly into the exhaust stream, upstream of the catalyticconverter 16. The level of ZDDP and the amount of oil injected can bevaried, depending upon the degree of deactivation required. Factors toconsider include the conditions of testing such as engine operatingconditions (e.g. engine speed and engine load), and the type of oil andpoisoning compounds to be studied. The engine can then run through acombination of high speed and load (to thermally deactivate thecatalyst), and low speed/low load conditions combined with injection ofthe oil into the exhaust stream (to deposit the poisons on the catalyticsurface). This combination of high and low temperature operation is runcyclically, until the desired level of deactivation is achieved. Ingeneral, exhaust gas temperatures during accelerated aging on an enginedynamometer or a laboratory reactor can be vary, from about 300° C.during low load and low speed operation, and up to about 1200° C. duringhigh load and high speed operation. More specifically, the exhaust gastemperatures can be vary, in the range of 300° C. to 1200° C.Alternatively, operating ranges can be from about 300° C. to about 600°C. during low speed and low load operation, or from about 600° C. toabout 1200° C. during high speed and high load operation.

[0086] The present invention includes a method of introducing thepoison-containing oil in to the exhaust stream 17. The process ofintroducing engine lubricating oil (with or without elevated levels ofpoisonous compounds) is critical. For instance, if oil is 1i dripped orinjected, preferably as a mist using a nozzle, into the exhaust stream,it could coke or oxidize at the point of introduction, and may 1) neverreach the catalyst washcoat surface, or 2) coke and block the nozzle orother device used to drip or inject the oil in to the exhaust stream.

[0087] In accordance with the method of the present invention, coking ofoil in the process of accelerated aging of a catalytic converter on anengine dynamometer or a laboratory reactor is prevented or minimized.Forcing the oil into the exhaust stream as a mist with the assistance ofhigh pressure nitrogen or other inert gas is one embodiment of thepresent invention. This assists in keeping the flow nozzle clear duringcertain types of catalyst aging.

[0088] Another embodiment of this invention is the introduction of bothhigh pressure nitrogen (or other inert gas) and water with the oil. Thewater can be dripped or sprayed into the manifold. Preferably, the waterintroduced as a mist using a nozzle. The oil, water and nitrogen have tobe introduced at predetermined rates and pressures, sufficient to keep aclear flow through the injection nozzle or orifice. This method resultsin the emulsification of the oil by the water. As the mixture comes incontact with the hot walls of the injector and tube, some coking willbegin. However, the water in the emulsion evaporates at thesetemperatures, and thus cleans out the oil flow passage. Thisself-cleaning mechanism is critical to keeping a continuous flow of oilinto the exhaust gas stream for the entire duration of oil injectionduring certain arduous the accelerated aging test protocol.

[0089] Depending the testing protocol, including engine operationconditions, and the type of engine and exhaust system the nitrogenpressure can be from about 4 to about 100 psig, and typically variedbetween 4 and 20 psig, with a corresponding flow rate typically rangingbetween 0.2 SCFM and 1.2 SCFM. The oil injection can typically be variedbetween 10 and 100 cc/hr, and specifically between 20 and 50 cc/hr. Thewater is injected at a rate typically varying between 0 and 200 cc/hr.Specifically, between 40 and 100 cc/hr.

[0090] The method and apparatus of the present invention areparticularly useful when the emission treatment device comprises acatalyst supported on a substrate. In preferred embodiments the catalystcomprises a catalyst composition comprising a support; and at least onecatalytic material selected from the group consisting of at least oneplatinum group metal component, gold and silver. The platinum groupmetal component can be selected from at least on component selected fromthe group consisting of platinum, palladium, rhodium, ruthenium andiridium.

[0091] The present invention is particularly useful to simulate catalystpoisoning of motor vehicle catalysts and filters including catalyticfilters.

[0092] Useful diesel engine emission treatment filters include wall flowfilters which may or may not be catalyzed. Oxidation catalystscomprising a platinum group metal dispersed on a refractory metal oxidesupport are known for use in treating the exhaust of diesel engines inorder to convert both HC and CO gaseous pollutants and particulates,i.e., soot particles, by catalyzing the oxidation of these pollutants tocarbon dioxide and water. Reference is made to commonly assigned U.S.Ser. No. 09/191,603 herein incorporated by reference for a review ofdiesel catalysts and a disclosure of substrates useful to treat dieselengine exhaust emissions.

[0093] Catalyzed soot filters are known from references such U.S. Pat.Nos. 4,510,265 and 5,100,632. These references disclose the use ofcatalyzed soot filters in diesel exhaust streams. Reference is also madeto SAE Technical Paper Ser. No. 860298, update on the evaluation ofdiesel particulate filters for underground mining by A. Lawson, et al.

[0094] Many references disclose the use of wallflow filters whichcomprise catalysts on or in the filter to filter and burn off filteredparticulate matter. A common construction is a multi-channel honeycombstructure having the ends of alternate channels on the upstream anddownstream sides of the honeycomb structure plugged. This results incheckerboard type pattern on either end. Channels plugged on theupstream or inlet end are opened on the downstream or outlet end. Thispermits the gas to enter the open upstream channels, flow through theporous walls and exit through the channels having open downstream ends.The gas to be treated passes into the catalytic structure through theopen upstream end of a channel and is prevented from exiting by theplugged downstream end of the same channel. The gas pressure forces thegas through the porous structural walls into channels closed at theupstream end and opened at the downstream end. Such structures areprimarily disclosed to filter particles out of the exhaust gas stream.Often the structures have catalysts on or in the substrate which enhancethe oxidation of the particles. Typical patents disclosing suchcatalytic structures include U.S. Pat. Nos. 3,904,551; 4,329,162;4,340,403; 4,364,760; 4,403,008; 4,519,820; 4,559,193 and 4,563,414.

[0095] A useful motor vehicle catalyzed substrate include three-waycatalysts designed to oxidize hydrocarbons and carbon monoxide, and toreduce nitrogen oxides. Useful catalysts and catalyst structures aredisclosed in WO95/35152, WO95/00235 and WO96/17671, and U.S. Pat. Nos.4,714,694 and 5,057,483 hereby incorporated by reference.

[0096] Such catalysts can be in the form of a catalyst compositionsupported on a substrate such as a ceramic or metal monolith. Thecatalyst can be a coating on the substrate of one or more catalystcomposition layers. Useful catalyst compositions can be in the form ofone or more coatings. A useful and preferred catalytically activecomponents are precious metals, preferably a platinum group metal and asupport for the precious metal. Useful catalytically active componentsinclude at least one of palladium, platinum, rhodium, ruthenium, andiridium components, with platinum, palladium and/or rhodium preferred.Precious metals are typically used in amounts of up to 300 g/ft³,preferably 5 to 250 g/ft³ and more preferably 25 to 200 g/ft³ dependingon the metal.

[0097] Preferred supports are refractory oxides such as alumina, silica,titania, and zirconia. A catalyst system useful with the method andapparatus of the present invention comprises at least one substratecomprising a catalyst composition located thereon. The compositioncomprises a catalytically active material, a support and preferably anoxygen storage component.

[0098] The platinum group metal component support components useful inthe composition of the present invention includes at least onestabilized refractory compound, which is most preferably lanthanastabilized alumina, and additionally at least one unstabilizedrefractory compound selected from the group consisting of silica,alumina and titania compounds. Preferred first and second supports whichare not stabilized compounds can be activated compounds selected fromthe group consisting of alumina, silica, titania, silica-alumina,alumino-silicates, alumina-zirconia, aluminachromia, and alumina-ceria.In the composite of the present invention at least one of the first andsecond layer, preferably the first layer comprises at least onestabilized refractory compound, which is most preferably lanthanastabilized alumina, and additionally at least one refractory compoundselected from the group consisting of silica, alumina and titaniacompounds. The other layer, preferably the second layer comprises atleast one of the recited unstabilized refractory oxide supports.

[0099] Preferred oxygen storage components useful in these catalystshave oxygen storage and release capabilities. The oxygen storagecomponent is any such material known in the art, preferably at least oneoxide of a metal selected from the group consisting of rare earthmetals, and most preferably a cerium or praseodymium compound, with themost preferred oxygen storage component being cerium oxide (ceria). Theoxygen storage component can be present at least 5 wt. % and preferablyat least 10 wt. % and more preferably at least 15 wt. % of the catalystcomposition.

[0100] These catalysts may further contain a nickel or iron component tosuppress hydrogen sulfide. Stabilizers can be in either the first orsecond layers, and are preferably in the first layer. Stabilizers can beselected from at least one alkaline earth metal component derived from ametal selected from the group consisting of magnesium, barium, calciumand strontium, preferably strontium and barium. Zirconium components inthe first and/or second layers is preferred and acts as both astabilizer and a promoter. Rare earth oxides act to promote thecatalytic activity of the first layer composition. Rare earth metalcomponents are preferably selected from the group consisting oflanthanum metal components and neodymium metal components.

[0101] For typical automotive exhaust gas catalytic converters, thecatalyst composite which includes a monolithic substrate generally maycomprise from about 0.50 to about 6.0, preferably about 1.0 to about 5.0g/in³ of catalytic composition coating.

[0102] When the compositions, including the poison compounds orprecursors thereof of the present invention, are applied as one or morethin coatings to a monolithic carrier substrate, the proportions ofingredients are conventionally expressed as grams of material per cubicinch of catalyst as this measure accommodates different gas flow passagecell sizes in different monolithic carrier substrates. Platinum groupmetal components are based on the weight of the platinum group metal.

[0103] Any suitable substrate, also referred to as a carrier, may beemployed, such as a monolithic carrier of the type having a plurality offine, parallel gas flow passages extending therethrough from an inlet oran outlet face of the carrier, so that the passages are open to fluidflow therethrough (see above discussion regarding wall flow carriers).The passages, which are essentially straight from their fluid inlet totheir fluid outlet, are defined by walls on which the catalytic materialis coated as a “washcoat” so that the gases flowing through the passagescontact the catalytic material. The flow passages of the monolithiccarrier are thin-walled channels which can be of any suitablecross-sectional shape and size such as trapezoidal, rectangular, square,sinusoidal, hexagonal, oval, circular. Such structures may contain fromabout 60 to about 600 or more gas inlet openings (“cells”) per squareinch of cross section. The ceramic carrier may be made of any suitablerefractory material, for example, cordierite, cordierite-alpha alumina,silicon nitride, zircon mullite, spodumene, alumina-silica magnesia,zircon silicate, sillimanite, magnesium silicates, zircon, petalite,alpha alumina and aluminosilicates. The metallic honeycomb may be madeof a refractory metal such as a stainless steel or other suitable ironbased corrosion resistant alloys.

[0104] Such monolithic carriers may contain up to about 700 or more flowchannels (“cells”) per square inch of cross section, although far fewermay be used. For example, the carrier may have from about 60 to 600,more usually from about 200 to 400, cells per square inch (“cpsi”).

[0105] The discrete form and second coats of catalytic material,conventionally referred to as “washcoats”, as well as the poisoncompounds of the present invention, can be coated onto a suitablecarrier with, preferably, the first coat adhered to the carrier and thesecond coat overlying and adhering to the first coat. With thisarrangement, the gas being contacted with the catalyst, e.g., beingflowed through the passageways of the catalytic material-coated carrier,will first contact the second or top coat and pass therethrough in orderto contact the underlying bottom or first coat. However, in analternative configuration, the second coat need not overlie the firstcoat but may be provided on an upstream (as sensed in the direction ofgas flow through the catalyst composition) portion of the carrier, withthe first coat provided on a downstream portion of the carrier. Thus, toapply the washcoat in this configuration, an upstream longitudinalsegment only of the carrier would be dipped into a slurry of the secondcoat catalytic material, and dried, and the undipped downstreamlongitudinal segment of the carrier would then be dipped into a slurryof the first coat catalytic material and dried.

[0106] Alternatively, separate carriers may be used, one carrier onwhich the first coat is deposited and a second carrier on which thesecond coat is deposited, and then the two separate carriers may bepositioned within a canister or other holding device and arranged sothat the exhaust gas to be treated is flowed in series first through thecatalyst containing the second coat and then through the catalystcontaining the first coat thereon. However, as indicated above, it ispreferred to utilize a catalyst composition in which the second coatoverlies and adheres to the first coat because such configuration isbelieved both to simplify production of the catalyst composition and toenhance its efficacy.

[0107] As indicated above, the catalyst composition, and poisoncompounds, of the present invention can be in the form of a pellet or inthe form of layer supported on a substrate. The preferred substrate is ahoneycomb catalyst carrier which can be made of metal or ceramic. Thecomposition, in the form of a layer, can be supported on the substrate.A slurry of the composition can be used to coat a macrosize carrier. Thecatalyst composition can be coated as a layer on a monolithic substrategenerally which can comprise a loading of from about 0.50 to about 6.0,preferably about 1.0 to about 5.0 g/in³ of catalytic composition basedon grams of composition per volume of the monolith.

[0108] The present invention is illustrated further by the followingexamples which are not intended to limit the scope of this invention.Various of the Examples include microprobe X-ray maps of a cross-sectionof catalyst coated ceramic honeycomb walls. When viewing the maps inblack and white, the lighter areas are an indication of catalystcomposition poisons (e.g. phosphorous or zinc compounds).

EXAMPLES

[0109] Laboratory Method for Z—P Poisoning of TWC Catalyst

Example 1

[0110] Reference Catalyst A

[0111] Reference catalyst A is a typical TWC catalyst with a Pd loadingof 130 g/ft³. It is a two layered catalyst with the bottom layer having0.43 g/in³ of Pd supported on alumina and additionally g/in³ of alumina,0.26 g/in³ of a ceria/zirconia composite, 0.62 g/in³ of ceria, 0.2 g/in³of zirconia, 0.09 g/in³ of BaO, 0.06 g/in³ Nd₂O₃, 0.09 g/in³ La₂O₃, 0.92g/in³ NiO; and a top layer having 0.70 g/in³ of Pd supported on alumina,0.2 g/in³ of a ceria/zirconia composite, 0.1 g/in³ of zirconia, 0.10g/in³ Nd₂O₃, 0.10 g/in³ La₂O₃, 0.1 g/in³ of SrO. The two layeredcatalyst was supported on a ceramic honeycomb substrate having 400 cellsper square inch, and being 3 inches long with a racetrack shape. Thecatalyzed honeycomb was oven aged in dry air at 750° C. for 4 hoursbefore modification using the zinc-phosphorous poisoning.

Example 2

[0112] Zn-P Modification Method Catalyst B

[0113] 20 g of ZnO was made into a slurry by adding water to about 150 g. The slurry was mixed for about 30 minutes. 12 g of the diammoniumhydrogen phosphate was added to 56 g of the ZnO slurry. The addition ofthe phosphate component made the ZnO a coat-able slurry. The Zn—P slurrywas then coated over cores of the aged catalyst A to make a wash coatloading of about 0.5 g/in3. The ZnO and P205 concentration based ontotal weight of substrates and wash coat was about 3.2 and 6%respectively. After coating the catalyst was dried and calcined at 550°C. for 2 hrs.

[0114] Microprobe, X-ray maps, of the Zn—P poisoned catalysts showed aclear layer of Zn—P on the surface of the catalyst, especially at thetop layer. An alumina coated sample is used as a reference. See FIGS. 2and 3. This was the case for the Zn—P poisoned catalyst measured freshor after 1050° C. aging. The X-ray maps of the ZnO and P lab preparedsamples resemble to great extent the engine poisoned samples usinglubricant containing predetermined amount of Zn and P. FIG. 4 shows thecomparison between an engine-aged catalyst Phosphorus profile and thatof a laboratory-prepared Zn/P doped catalyst.

Example 3

[0115] Testing Procedure

[0116] The hydrocarbon oxidation activity of the reference catalysts andthe Zn—P poisoned catalysts were measured as fresh and aged. The 750° C.conditioned catalysts was considered fresh. These catalysts were alsooven aged at 1050° C. in dry air for 4 hrs. (Aged catalyst).

[0117] The catalysts were evaluated in a mini-reactor using coredsamples from the above referenced substrates (the cores had adiameter=0.5 cm and length=2.5 cm). The hydrocarbon conversion activitywas measured in a temperature ramp up from 150 to 550° C. The gascomposition is made up of propene=200 PPM, propane=200 PPM, methane=100PPM, O2=5%, NO=500 PPM, 10% steam, and balance N2. The conversion wasmeasured at a space velocity of 50,000/hr.

Example 4

[0118] Comparison of Fresh Reference and Poisoned Catalysts

[0119] Catalyst B prepared by addition of Zn—P to catalyst A (poisonedby the procedure outlined above) showed severe deactivation forhydrocarbon conversion activity (FIG. 5). This is similar to the vehicleaged catalysts in real applications. Therefore, by using a simplelaboratory procedure we were able to mimic ZnO—P poisoning of catalyticconverter on vehicles after extended driving (over 100,000 miles). Thisapproach for the Zn—P poisoning should allow for the simulation ofcatalytic converter poisoning in a laboratory environment with minimalcost.

[0120] The ZnO—P modified catalyst B was also aged at 1050° C. and theresults of hydrocarbon conversion activity was compared to unmodifiedreference catalyst A in FIG. 6. The results again show the severedeactivation effect of the Zn—P poisoning using the lab procedure(Example 3) on the catalyst performance. After aging this method ofpoisoning showed again good resemblance to the Zn—P poisoned catalyst inreal application. By using the Zn—P laboratory poisoning method we wereable to demonstrate its use as a method to mimic real poisoning by Zn—Pof the catalytic converter during actual driving and accumulation ofthousands of miles. The advantage of this method is to demonstrate theability to mimic in a lab setup, the Zn—P poisoning that occurs invehicles after extended driving. This test would, therefore, predict thetolerability of the catalytic converters to Zn and P poisoning.

[0121] Engine Aging Method for Zn—P Poisoning of TWC Catalyst

Example 5

[0122] Two catalyst samples, were aged on an engine for 75 hours in acyclic exothermic aging such as that described in the SAE paper 972906(Replication of 50 k vehicle-aged catalyst performance using an enginedynamometer aging cycle: P. Johnson, et al., October 1997). Bothcatalysts were of the same type, 64 cubic inches, 3.03×5.78×4.5 in., 400cpsi and with a precious metal loading of 180 g/ft3, 2/27/1 Pt/Pd/Rh.After the high temperature aging, the catalysts were tested for lightoff activity on an engine bench stand, to ensure that they had been agedidentically. The light off test was run with clear indolene as the fuel,a space velocity of 80,000/hr, and an air/fuel perturbation of 0.5 @ 1.0Hz. FIG. 7 shows that the light off curves are, indeed, identical.

[0123] The same catalysts (Sample numbers GF02340 & GF02341) were thenaged for an additional 24 hours, at 450° C. catalyst inlet temperatureand steady state, with oil injected into the exhaust just ahead ofsample number GF02341. The oil contained 15 times the nominal level ofZDDP as an additive. During this time, the oil flowed into the exhauststream in a steady flow, with a total of approximately 0.75 quartsduring the 24-hour period. After this poison aging, the catalysts weretested again for light off. From FIG. 8, it can be seen that both thecatalysts lost activity after this low temperature aging. However, theone with the oil injection was much worse due the phosphorus poisoningeffect.

[0124] After the second light off, the catalysts were run at 600° C. forabout 1 hour to purge them of sulfur accumulated during the agingprocess. Then, the catalysts were evaluated for light off again. FIG. 9shows that GF02340 fully recovered due to the removal of sulfur. GF02341was still poorer than GF02340, due to the effect of the poisoning due tophosphorus and zinc.

[0125] The same catalysts were then tested according to a 1975 FTP testrun on a 1998 Ford Crown Victoria vehicle. The FTP 75 test is describedin Title 40 Code of Federal Regulations, Part 8 b (40 CFR #86) and inparticular 40 CFR 86.130-78 to 86.140-82 (1987). FIG. 10 shows thetailpipe Hydrocarbon emissions for these two catalysts. Clearly, the oilinjection has a detrimental effect on hydrocarbon performance of samplenumber GF02341. Likewise, FIG. 11 and FIG. 12 show the relative CO andNOx emissions. From all of these tests, it is clear that oil injectioninto the exhaust stream at low temperature results in poisoning of thecatalyst.

Example 6

[0126] Two catalyst samples were evaluated as washcoats on ceramichoneycomb supports being 42 cubic inches, with dimensions of2.68×5.68×3.15 inches, and having 400 cpsi (Cells per square inch). Thecatalyst compositions were substantially the same as in Example 1 exceptthat they had a precious metal loading of 200 g/ft3 of palladium. Thesupported catalysts were aged on an engine for 75 hours in a cyclicexothermic aging such as that described in the SAE paper 972906(Replication of 50 k vehicle-aged catalyst performance using an enginedynamometer aging cycle: P. Johnson, et al., October 1997). After thehigh temperature aging step, the engine was cycled down to idle speed,and no load. Cooling fans were turned on automatically during thisportion of the cycle to further cool down the catalytic converter, toeither 400° C. or 600° C. After a specified period of time (20 minutesin this example), The engine was brought back to high speed and load forthe next period (20 minutes in this example). This cycling of high andlow speed/load was repeated for a total of 75 hours of aging. After theengine aging, the catalysts were tested for light off activity on anengine bench. The light off test was run with clear indolene as thefuel, a space velocity of 80,000/hr, and an air/fuel perturbation of 0.5@ 1.0 Hz. FIG. 14 shows that the catalyst with oil injection wasseverely deactivated, compared to the catalyst that was only subjectedto cyclic high temperature aging. The oil injected had DZZP level of 1.5weight percent which is 15 times the nominal level of 0.1 weightpercent. The aged catalysts were then cut open and analyzed for chemicalcomposition and poison accumulation profiles. FIGS. 15 and 16 show thephosphorus and zinc, with alumina used as a reference, depositionprofiles for the catalysts with and without oil injection. It can beclearly seen that there is a certain amount of phosphorus deposition inthe catalyst washcoat from the oil consumption of the engine itself. Inaddition, the process of injecting oil into the exhaust results in asignificant accumulation of phosphorus and other compounds on thesurface of the washcoat.

[0127] This is a replication of in-field failures, where the emissioncontrol system failed prematurely, due to excessive oil consumption andaccumulation of poisonous materials on the catalytic surface.

Example 7

[0128] Two catalyst samples were evaluated as washcoats on ceramichoneycomb supports being 42 cubic inches, with dimensions of2.68×5.68×3.15 inches, and having 400 cpsi (Cells per square inch). Thecatalyst compositions were substantially the same as in Example 1 exceptthat they had a precious metal loading of 200 g/ft3 of palladium. Thesupported catalysts, were aged on an engine for 75 hours in a cyclicexothermic aging such as that described in the SAE paper 972906(Replication of 50 k vehicle-aged catalyst performance using an enginedynamometer aging cycle: P. Johnson, et al., October 1997). After thehigh temperature aging step, the engine was brought down to idle speed,and no load. In this example, the engine used was a 5.7 L V8 engine.During the high temperature portion, the engine was run at 2800 rpm anda manifold vacuum of 18 inches of mercury (which is an indication of theload on the engine). During the low temperature step, the engine was runat 1200 rpm and a manifold vacuum of 19 inches of mercury. Cooling fanswere turned on automatically during this portion of the cycle to furthercool down the catalytic converter, to 600° C. After a specified periodof time (20 minutes in this example), the engine was brought back tohigh speed and load for the next period (20 minutes in this example).This cycling of high and low speed/load was repeated for a total of 75hours of aging. During the entire aging, oil was injected into theexhaust stream along with water and nitrogen, at the inlet of one of thecatalysts only. The nitrogen was introduced at a pressure of 15 psig anda flow rate of approximately 0.5 SCFM. The oil was pumped in at a flowrate of 40 cc/hr and the water was pumped in at a flow rate of 80 cc/hr.After the engine aging, the catalysts were tested for light off activityon an engine bench. The light off test was run with clear indolene asthe fuel, a space velocity of 80,000/hr, and an air/fuel perturbation of0.5 @ 1.0 Hz. FIG. 17 shows that the catalyst with oil injection wasseverely deactivated, compared to the catalyst that was only subjectedto cyclic high temperature aging.

[0129] The aged catalysts were then cut open and analyzed for chemicalcomposition and poison accumulation profiles. FIGS. 18 and 19 show thephosphorus deposition profiles for the catalysts with and without oilinjection. It can be clearly seen that there is a certain amount ofphosphorus deposition in the catalyst washcoat from the oil consumptionof the engine itself. In addition, the process of injecting oil into theexhaust results in a significant accumulation of phosphorus and othercompounds on the surface of the washcoat. This is a replication ofin-field failures, where the emission control system failed prematurely,due if to excessive oil consumption and accumulation of poisonousmaterials on the catalytic surface.

What is claimed is:
 1. A method comprising the steps of: combining anemission treatment device selected from at least one of a catalyst and afilter, and at least one poison compound having at least one componentselected from the group consisting phosphorous, zinc and sulfur to forma poisoned emission treatment device; heating the poisoned emissiontreatment device to from about 200° C. to about 1100° C. for from about0.5 hours to about 24 hours to form a calcined emission treatmentdevice; and evaluating the activity of the calcined emission treatmentdevice.
 2. A method comprising the steps of: operating a gasoline ordiesel engine, having an exhaust gas outlet or an exhaust gas manifoldoutlet; passing an exhaust gas stream comprising pollutants selected atleast one pollutant component selected from the group consisting ofcarbon monoxide, hydrocarbons and nitrogen oxides, volatile organiccomponents and dry soot, from the exhaust gas outlet or the exhaust gasmanifold outlet of the engine to an emission treatment device selectedfrom at least one of a catalyst and a filter; adding to the exhaust gasstream at a location between the exhaust gas outlet or the exhaust gasmanifold outlet and the emission treatment device at least one poisoncompound having at least one component selected from the groupconsisting phosphorous, zinc and sulfur; contacting the exhaust gas withthe emission treatment device to form a poisoned emission treatmentdevice; evaluating the catalytic activity of the exhaust treatmentcatalyst to determine the conversion percent of at least one pollutantcomponent by the catalyst, the light-off temperature of at least onepollutant component at the catalyst, and/or the efficiency of thefilter.
 3. A method comprising the steps of: operating an gasoline ordiesel engine having at least one oil pan in which lubricating oil islocated, having an exhaust gas outlet or an exhaust gas manifold outlet;passing an exhaust gas stream comprising pollutants selected at leastone pollutant component selected from the group consisting of carbonmonoxide, hydrocarbons and nitrogen oxides, volatile organic componentsand dry soot, from the exhaust gas outlet or the exhaust gas manifoldoutlet of the engine to an emission treatment device selected from atleast one of a catalyst and a filter; adding to the oil at least onepoison compound having at least one component selected from the groupconsisting phosphorous, zinc and sulfur in an amount in excess of theamount functionally required for the oil to function; contacting theexhaust gas with the emission treatment device; and evaluating thecatalytic activity of the exhaust treatment catalyst to determine theconversion percent of at least one pollutant component by the catalyst,the light-off temperature of at least one pollutant component at thecatalyst, and/or the efficiency of the filter.
 4. The method as recitedin claims 1, 2 or 3 wherein the emission treatment device comprises acatalyst supported on a substrate.
 5. The method as recited in claim 4wherein the poisoned catalyst is heated at from about 300° C. to about800° C.
 6. The method as recited in claim 5 wherein the poisonedcatalyst is heated at from about 300° C. to about 500° C.
 7. The methodas recited in claim 4 wherein the catalyst comprises a catalystcomposition comprising: a support; and at least one catalytic materialselected from the group consisting of at least one platinum group metalcomponent, gold and silver.
 8. The method as recited in claim 7 whereinthe selected from the platinum group metal component is selected fromthe group consisting of platinum, palladium, rhodium, ruthenium andiridium.
 9. The method as recited in claim 4 wherein the catalyst is agaseous emissions exhaust catalyst.
 10. The method as recited in claim 9wherein the gaseous emissions exhaust catalyst is useful to treat atleast one pollutant component selected from the group consisting ofcarbon monoxide, hydrocarbons and nitrogen oxides, volatile organiccomponents and dry soot.
 11. The method as recited in claim 4 whereinthe at least one poison compound is selected from the group of acompounds comprising phosphorous, a compound comprising zinc compound, asulfur compound, a compound comprising phosphorous and zinc, a compoundcomprising zinc and sulfur and a compound comprising phosphorous zincand sulfur.
 12. The method as recited in claim 11 wherein: the compoundcomprising phosphorous is selected from the group consisting of ammoniumhydrophosphate, phosphoric acid, phosphorus acid, and organo phosphoruscompounds; the compound comprising zinc is selected from the groupconsisting of zinc oxide, zinc nitrate, zinc sulfate, zinc carbonate andorgano zinc compounds; and the compound comprising phosphorous and zincis selected from the group consisting of a mixture of zinc oxide andammonium hydrophosphate, zinc dithio phosphate, and zinc phosphate. 13.The method as recited in claim 12 wherein: the compound comprisingphosphorous and zinc is a slurry of zinc oxide and ammoniumhydrophosphate; coating the catalyst with the slurry; and calcining thecoated slurry.
 14. The method as recited in claim 12 wherein the amountof the catalyst poison compound is from about 1.0 to about 20 weightpercent of the catalyst.
 15. The method as recited in claim 4 whereinthe step of evaluating the catalytic activity of the gaseous emissionsexhaust catalyst comprises contacting a synthetic gas comprising atleast one pollutant component with the poisoned catalyst atpredetermined conditions of temperature, time and pollutant componentconcentration to determine the conversion percent of at least onepollutant component and/or the light-off temperature of at least onepollutant component.
 16. The method as recited in claim 4 wherein theemission treatment device comprises a catalyst supported on a substrate.17. The method as recited in claim 4 wherein the amount of the catalystpoison compound is from about 1.0 to about 20 weight percent of thecatalyst.
 18. The method as recited in claim 3 wherein the amount ofpoison is greater than 0.15 percent of the oil.
 19. The method asrecited in claim 3 wherein the amount of poison is from about 0.15 toabout 0.5 weight percent of the oil.
 20. The method as recited in claims2 or 3 wherein the step of operating the engine further comprisescycling the operating conditions at least once from low load and/or lowspeed to high load and/or high speed to result in the exhaust gas streamcycling from a temperature in the range of from 200° C. to 600° C. to atemperature in the range of from 600° C.
 21. The method as recited inclaim 2 further comprising the step of adding an inert gas to the poisoncompound at a location between the exhaust gas outlet or the exhaust gasmanifold outlet and the emission treatment device.
 22. The method asrecited in claim 21 where the poison is in a composition comprisingengine oil is added in the form of a mist.
 23. The method as recited inclaim 22 the oil is added in the form of a mist.
 24. The method asrecited in claim 21 further comprising the step of adding an water tothe mixture of the inert gas and the composition comprising poison andoil at a location between the exhaust gas outlet or the exhaust gasmanifold outlet and the emission treatment device.
 25. An articlecomprising: an emission treatment device selected from at least one of acatalyst and a filter; and an over coat on at least part of the emissiontreatment device of a predetermined amount at least one poison compoundhaving at least one component selected from the group consistingphosphorous, zinc and sulfur.
 26. The article as recited in claim 25,wherein the exhaust treatment catalyst has an exhaust gas treatmentcatalyst composition: a support; at least one platinum group metalcomponent selected from the group consisting of platinum, rhodium,ruthenium and iridium components.
 27. The article as recited in claim 25wherein the catalyst is supported on a substrate having channelextending from an inlet end to an outlet end and the poison is depositedin varying concentrations from the inlet to the outlet.
 28. The articleas recited in claim 27 wherein the poison is deposited in zones havingdifferent concentrations from the inlet to the outlet.
 29. The articleas recited in claim 28 wherein the poison is deposited in an inlet zonehaving a higher concentrations then an outlet zone located between theinlet zone and the outlet end.
 30. An apparatus comprising: a gasolineor diesel engine, having an exhaust gas outlet or an exhaust gasmanifold outlet; an emission treatment device selected from at least oneof a catalyst and a filter; an exhaust gas conduit communicating betweenthe exhaust gas outlet or an exhaust gas manifold outlet and theemission treatment device; a means to feed to the emission treatmentdevice the at least one poison or a compound capable of forming thepoison and having at least one component selected from the groupconsisting phosphorous, zinc and sulfur, to form an over coat on atleast part of the emission treatment device, of a predetermined amountof the at least one poison compound; a means to evaluate the emissiontreatment device to determine the conversion percent of at least onepollutant component by the catalyst, the light-off temperature of atleast one pollutant component at the catalyst, and/or the efficiency ofthe filter.
 31. The apparatus as recited in claim 30 further comprising:a feed port into the conduit at a location between the exhaust gasoutlet or the exhaust gas manifold outlet and the emission treatmentdevice, wherein the at least one poison or a compound capable of formingthe poison is fed to the emission treatment device through the feedport.
 32. The apparatus as recited in claim 31 further comprising ameans to feed an inert gas into the conduit.
 33. The apparatus asrecited in claim 32 further comprising a means to feed water into theconduit.
 34. The apparatus as recited in claim 30 further comprising amanifold in communication with the conduit and the emission treatmentdevice and means to feed to the manifold the compound capable of forminga poison and an inert gas.
 35. The apparatus as recited in claim 34further comprising a means to water to the manifold.